ADSL Training Log TroubleShooting

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Before 12.4(11)XJ, all fixed and modular ADSL routers could use the command "dsl enable-training-log" to retrieve information about the events during the ADSL training. This command however retrieved the log file from the ADSL chipset at showtime and displayed it when the "sh dsl int" command was used.

The disadvantage of this is that events that events that caused failures (line flaps, CRC errors) could not be seen from the training log.

In 12.4(11)XJ sub-commands to the "dsl enable-training-log" command have been added that allow users to capture the log on different events.

This command enables the training log to record the firmware debug messages. The log can be retrieved from the ADSL chipset after the ADSL line goes into Showtime or after the ADSL comes out of Showtime or whenever the user enters the show dsl interface atm command. The delay option can be used to delay the retraining of the line after the log is retrieved from the chipset. Because only one log buffer is used to capture the log, the subsequent line state changes will overwrite the buffer. The delay option allows the user enough time to capture the log from the output of the show dsl interface atm command. By default, the training log is disabled.

Download the document Training Log COllection using IOS 12.4(11)XJ and later for detailed instructions.

For additional resources for debugging ADSL issues visit the FAQ

ADSL training log collection steps

1. Training log collection for an unstable DSL connection

The following steps are used when the training log needs to collected after the DSL line comes out of the show time state (in case of line flapping issues). The retrieved log from the ADSL chipset is stored in a buffer and displayed in the output of "show dsl int atm" command. a) Enable the training log collection for failure cases only, dsl enable-training-log failure delay <nsecs> (under "interface atm 0" sub-config)

The "delay <nsecs> specifies how many seconds to wait before retraining the line once the log is retrieved from the chipset. This will give enough time to the user to capture the output of "show dsl int atm" command, before the log buffer overwritten. The <nsecs> varies from 0 to 600 seconds. The default is 0 seconds.

The following steps are used when the training log needs to be collected after the DSL line successfully trains up and enter the showtime state. a) Enable the training log collection for showtime cases only,dsl enable-training-log showtime delay <nsecs> (under "interface atm 0" sub-config)

The "delay <nsecs> specifies how many seconds to wait before retraining the line once the log is retrieved from the chipset. This will give enough time to the user to capture the output of "show dsl int atm" command, before the log buffer overwritten. The <nsecs> varies from 0 to 600 seconds. The default is 0 seconds. b) Enable the DSL debug, debug atm events c) Wait for the following message *Jul 8 09:36:30.671: DSL(ATM0): Training log collection completed d) Capture the output of "show dsl int atm0"

3. On demand training log collection

The commands "dsl enable-training-log showtime" and "dsl enable-training-log failure" are used when the training log needs to be collected just after the line goes into showtime and just after the line goes down respectively. These previously collected log files are displayed in the output of "show dsl int atm0". But, if the log needs to be retrieved from the chipset during the execution of "show dsl int atm0", then "dsl enable-training-log ondemand" needs to be used. Use this command only when the line is in Showtime.

1. Dsl enable-training-log command

To enable the retrieval of the digital subscriber line (DSL) training log, use the dsl enable-training-log command in interface configuration mode. To disable retrieval of the DSL training log, use the no form of this command. dsl enable-training-log[always | showtime | failure | ondemand] [delay <nsecs>]no dsl enable-training-logSyntax Description:

Option

Explanation

always

The log is read both after show time and for failure cases. The "show dsl int atm0" will display the previously collected log file.

showtime

The log is read only after show time and not for failure cases. The "show dsl int atm0" will display the previously collected log file.

failure

The log is read only for failure cases. The log is collected when (a) the line fails to train up, and, (b) the line comes out of showtime. The "show dsl int atm0" will display the previously collected log file.

ondemand

The log is read when "show dsl int atm0" is executed. The log is collected during the execution of "show dsl" and then it will be displayed.

delay <nsecs>

Specifies how many seconds to wait after the log is retrieved form the chipset. When the line is flapping, the log buffer will be continuously overwritten after line failures. This will not give enough time for the user to capture the log file. Using this command, the user can specify the number of seconds to be waited after the log is generated and before the next training of the line. The <nsecs> varies from 0 to 600 seconds. The default is 0 seconds.

2. Debug messages for ADSL log generation events

New debug messages are generated before starting the collection of ADSL training log files and after the completion of the training log files. Enable, "debug atm event" to generate these messages. *Jul 8 09:36:07.759: DSL(ATM0): Training log collection started (log size 236871)...